The subject matter discussed in the background section should not be assumed to be prior art merely as a result of its mention in the background section. Similarly, a problem mentioned in the background section or associated with the subject matter of the background section should not be assumed to have been previously recognized in the prior art. The subject matter in the background section merely represents different approaches, which in and of themselves may also be inventions.
The threat of chemical, biological, and/or radiological attacks has intensified over the last few years. Chemical, biological, and/or radiological attacks are difficult to pre-empt and may cause mass destruction. Early detection and warnings to alert the public or occupants of an area, can be critical in minimizing and controlling the amount of damage caused by chemical, biological, and/or radiological attacks. Chemical, biological, and/or radiological attacks may cause serious injuries, severe health problems and even death in many cases. At the very least, chemical, biological, and/or radiological attacks impair the individual's ability to function. There is a need to detect these attacks as early as possible to minimize the negative effects of the chemical, biological, and/or radiological attack. One common way to protect against attacks is to sample the air and do chemical, radiological, and/or biological analysis on the sample. However, the problems with this approach include the following, chemical and biological detection devices are expensive, it is hard to detect all chemicals and biologicals and, most importantly, it can take anywhere from several minutes to several hours to run tests on the air samples. Also chemical detection is short range because air is sampled only in the immediate vicinity of the sensor.